Stanisław Kłosowski

Importance of water level dynamics for vegetation patterns in a natural percolation mire (Rospuda fen, NE Poland)

Although conservation of percolation mires is very important for the European biodiversity, our understanding of their functioning is still insufficient, as most of the studied sites are to some extent degraded. We present a study on the relationship between vegetation patterns, hydrochemical gradients and water level fluctuations carried out in the Rospuda valley (NE Poland), which was recently discovered for science as a uniquely preserved fully functioning percolation mire. Vegetation composition, mire water chemistry and water level dynamics were studied along five transects perpendicular to the valley. Eight major vegetation types were identified: brown moss-small and slender sedge fens, Sphagnum-small sedge fens, brown moss-tall sedge fens, tall sedge-reed fens, pine-birch fen woodlands and shrublands, spruce fen woodlands, inundated alder woodlands, alder spring fen woodlands. The seasonal dynamics of water table was revealed as the major factor explaining vegetation patterns. The studied chemical parameters were relatively homogeneous in the whole mire—there is a rather uniform type of mineral-rich nutrient-poor subsurface water all across the fen.

Habitat conditions of nymphaeid associations in Poland

A comparative analysis of the habitats of seven nymphaeid associations: Potamogetonetum natantis, Polygonetum natantis, Nuphar-Nymphaeetum albae, Nymphaeetum candidae, Nupharetum pumilae, Trapetum natantis and Nymphoidetum peltatae, was made within Poland. On the basis of water and substrate properties in the phytocoenoses analysed, it was demonstrated that most nymphaeid associations in Poland are distinctly associated with specific habitat conditions. Trapetum natantis occurs in neutral waters, poor in NH4 +, but markedly rich in dissolved organic matter, K+, PO4 3−, total Fe and Ca2+. It develops best on slightly acidic mineral substrates poor in Ca2+ and Na+, but markedly rich in PO4 3− and NO3. Nymphoidetum peltatae occurs in alkaline waters with high concentrations of Na+, C I− and NO3 − and with relatively high concentrations of K+ and PO4 3−. Its substrates are mineral, poor in SO4 2− and total N and rich in NO3 −, PO4 3− and K+. Nupharetum pumilae develops in waters extremely poor in SO4 2−, Na+, K+ and Ca2+, but rich in NO3 − and dissolved organic matter. It mainly occurs on organic substrates poor in Ca2+ and Na+. Nymphaeetum candidae and Potamogetonetum natantis are mainly found in mesotrophic waters. Polygonetum natantis mainly inhabits mineral substrates poor in NO3 −, Na+ and dissolved SiO2. Nupharo-Nymphaeetum albae occurs in a wide range of most types of habitat.

The Relationships Between Environmental Factors and the Submerged Potametea Associations in Lakes of North-eastern Poland

A comparative analysis of submerged Potametea communities in lakes of north-eastern Poland was conducted with respect to 16 water chemistry and 14 substrate parameters. The analysis of 187 relevés based on TWINSPAN clustering showed the existence of 8 aquatic vegetation types. Each of them is characterized by a strong dominance of one of the following macrophytes: Potamogeton lucens, P. perfoliatus, Myriophyllum spicatum, M. verticillatum, Elodea canadensis, Ceratophyllum demersum, Ranunculus circinatus and Hydrilla verticillata. The above vegetation types correspond to the plant associations distinguished using the Braun-Blanquet method (Potametum lucentis, Potametum perfoliati, Myriophylletum spicati etc.) It was demonstrated that among properties of water analysed, COD-KMnO4, SO42−, pH, Na+, K+, Ca2+, total hardness, total Fe, Cl− and colour appear to be most important in differentiating the habitats of the communities studied. In the case of substrates the properties which best differentiated the habitats compared were hydration, organic matter content, total N, PO43−, K+, dissolved SiO2, SO42−, Cl− and pH. Most of the aquatic plant communities investigated are distinct with respect to their phytocoenotic structure and ecology and could be good indicators of various types of habitats in lake ecosystems.

Habitat conditions of the phytocoenoses dominated by Luronium natans (L.) Rafin in Poland

Phytosociological and habitat studies of the phytocoenoses of Luronium natans have been conducted. The present results were compared with data on L. dortmanna and I. lacustris. It is demonstrated that the community of L. natans differs from the other two communities with respect to habitat conditions despite the fact that they have been reported to occur jointly and alongside in Lobelia lakes. It appears that significant differences between the communities are found not only regarding their waters, but also their substrates. L. natans dominated phytocoenoses are confined to oligotrophic, extremely soft waters, markedly poor in Ca2+, but richer in Na+ and SO42- than those of Lobelia and Isoëtes. Luronium natans develops best on acidic, highly hydrated substrates rich in organic matter, NO3− and total N. The results obtained indicate that L. natans and the phytocoenoses formed by it are characterized by their narrow ecological amplitude in Poland as opposed to those occurring in western Europe, which tolerate a relatively wide range of habitats. The present findings confirm the data from numerous works, which point to the weak competitive ability of the species compared with species typical of eutrophic waters.

Temporal and spatial variation of habitat conditions in the zonation of littoral plant communities

Abstract In this study, zonal distribution of littoral plant communities conformed with the spatial gradient and temporal variation of habitat conditions. In the water of the successive zones, pH and the concentrations of Na and K increased towards open water, whereas oxidability, the concentrations of NO 3 -N and PO 4 -P sediment organic matter content decreased. Hydration was lowest in the vegetational zone nearest to the open water, whereas the sediment Ca content was highest in this zone. Temporal changes often proceeded at a different rate for a given component or factor in each zone. Water plant communities, distinguished on the basis of floristic dominance as distinct syntaxa, could be good indicators of littoral habitat conditions.

Understanding the Long Term Ecosystem Stability of a Fen Mire by Analyzing Subsurface Geology, Eco-Hydrology and Nutrient Stoichiometry – Case Study of the Rospuda Valley (NE Poland)

We explored the background of differences in long–term stability between two parts in an undisturbed mire system (Rospuda fen, NE Poland). We re-constructed the Holocene history of the mire and compared it with current vegetation, water level dynamics, water chemistry and nutrient availability in two basins: A, where the mire terrestrialised a deep gyttja–filled lake, and B, where peatland developed directly on fluvial sands. The current vegetation of sedge–moss fens was described in 10 relevés from each basin, groundwater was sampled from piezometers and analysed for major ions, while its relative water level was recorded during three years. N and P content was measured in above ground vascular plant samples collected within the relevés. Fens in basin A were stable in the past, whereas fens in basin B switched between open and wooded or reed–dominated phases. In basin B, where trees are more abundant, we found higher water fluctuations, occurrence of river floods and a higher N:P ratio than in basin A. Our interpretation follows that the subsurface geology of fen basin may govern mire stability by determining its hydrological–buffering capacity, which may affect N:P ratios. Our results suggest that P–limited fens are more vulnerable for changes in water level.

Habitat conditions of the phytocoenoses of myriophylletum alterniflori lemée 1937 em. Siss. 1943, myriophylletum verticillati soó 1927 and myriophylletum spicati soó 1927 in Poland

Abstract A comparative analysis of the habitats of 28 Myriophylletum alterniflori, 23 Myriophylletum verticillati and 29 Myriophylletum spicati phytocoenoses from 50 lakes within northern and south-eastern Poland was conducted. On the basis of phytosociological data, and the physical and chemical properties of water and substrate in the analysed phytocoenoses, it is demonstrated that the phytosociological distinction of the associations studied, based on floristic dominance, is confirmed in the distinction of their habitats, both with respect to water and substrate chemistry. Myriophylletum alterniflori phytocoenoses in Poland are restricted to soft, oligotrophic-mesotrophic waters, poor in calcium and magnesium, and to substrates also poor in these elements. Myriophylletum verticillati phytocoenoses occur in mesotrophic or slightly eutrophic waters, poor in NO 3 N, PO 4 P and K on hydrated, organic and organic-mineral substrates, mostly rich in calcium. The phytocoenoses of Myriophylletum spicati grow in waters with a wide trophic amplitude, although their optimum development occurs in typical eutrophic waters. They may be indicators of substrates poor in organic matter.